Title:
Robust Parameter Design for Automatically Controlled Systems and Nanostructure Synthesis

dc.contributor.advisor Wu, C. F. Jeff
dc.contributor.author Dasgupta, Tirthankar en_US
dc.contributor.committeeMember Lu, Jye-Chyi
dc.contributor.committeeMember Tsui, Kwok-Leung
dc.contributor.committeeMember Vengazhiyil, Roshan Joseph
dc.contributor.committeeMember Ghosh, Soumen
dc.contributor.department Industrial and Systems Engineering en_US
dc.date.accessioned 2007-08-16T17:58:42Z
dc.date.available 2007-08-16T17:58:42Z
dc.date.issued 2007-06-25 en_US
dc.description.abstract This research focuses on developing comprehensive frameworks for developing robust parameter design methodology for dynamic systems with automatic control and for synthesis of nanostructures. In many automatically controlled dynamic processes, the optimal feedback control law depends on the parameter design solution and vice versa and therefore an integrated approach is necessary. A parameter design methodology in the presence of feedback control is developed for processes of long duration under the assumption that experimental noise factors are uncorrelated over time. Systems that follow a pure-gain dynamic model are considered and the best proportional-integral and minimum mean squared error control strategies are developed by using robust parameter design. The proposed method is illustrated using a simulated example and a case study in a urea packing plant. This idea is also extended to cases with on-line noise factors. The possibility of integrating feedforward control with a minimum mean squared error feedback control scheme is explored. To meet the needs of large scale synthesis of nanostructures, it is critical to systematically find experimental conditions under which the desired nanostructures are synthesized reproducibly, at large quantity and with controlled morphology. The first part of the research in this area focuses on modeling and optimization of existing experimental data. Through a rigorous statistical analysis of experimental data, models linking the probabilities of obtaining specific morphologies to the process variables are developed. A new iterative algorithm for fitting a Multinomial GLM is proposed and used. The optimum process conditions, which maximize the above probabilities and make the synthesis process less sensitive to variations of process variables around set values, are derived from the fitted models using Monte-Carlo simulations. The second part of the research deals with development of an experimental design methodology, tailor-made to address the unique phenomena associated with nanostructure synthesis. A sequential space filling design called Sequential Minimum Energy Design (SMED) for exploring best process conditions for synthesis of nanowires. The SMED is a novel approach to generate sequential designs that are model independent, can quickly "carve out" regions with no observable nanostructure morphology, and allow for the exploration of complex response surfaces. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/16300
dc.publisher Georgia Institute of Technology en_US
dc.subject Robust parameter design en_US
dc.subject Feedback control en_US
dc.subject Sequential design en_US
dc.subject Nanostructures en_US
dc.subject Multinomial GLM en_US
dc.title Robust Parameter Design for Automatically Controlled Systems and Nanostructure Synthesis en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Wu, C. F. Jeff
local.contributor.corporatename H. Milton Stewart School of Industrial and Systems Engineering
local.contributor.corporatename College of Engineering
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relation.isOrgUnitOfPublication 29ad75f0-242d-49a7-9b3d-0ac88893323c
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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